Rotary boring-drill.



. H. R. HUGHES.

ROTARY BORING DRILL.

APPLICATION FILED NOV. 1, 191a.

' 91,1Q4,241 "Patented Jan.5,1915.

" Howann :e. nuenns,

rarer; rare.

0F HOUSTON, TEXAS.

ao'ramz admire-DRILL.

To all whom it may concern:

Be it known that 1,..H0WAR1) R. HUGHES, a citizen'of the United States, residing at Houston, Texas, have invented a certain new and useful Improvement in Rotary Boring-Drillgof which the following is a full, clear, and exact description, such .aS will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to rotary boring drills of the type that are used for drilling wells, and particularly to drills of the type which comprisea head provided with rotatable cutters of substantially disk-shape that out the material, when the head rotates.

One object of my invention is'to provide a strong, serviceable and inexpensive rotary drill of simple construction that is particularly adapted for drilling in comparatively soft formations such, for example, as gumbo, shale, hard clay and soft rock.

Another object is to provide a rotary drill of the type referred to in which the cutters are so arranged on the head of the drill that the weight imposed on the drill causes the cutters to crush and disintegrate the material at the bottom of the hole, and the r0 tarymovement of the head causes the forward edges of the cutters t0 shearofi the material at the side of the hole and thus remain sharp'by rubbing constantly against the side Off the hole. And still another object is to provide a rotary drillof the type referred to that can be kept thoroughly lubricated when it is in operation, and which is so designed that itwillnot lose its clearance by reason of the cutters becoming dull" from dragging over the material without cutting same. v

Other objects and desirable features of my invention .v'ill' be hereinafter pointed Figure 1 of the drawings is a vertical sectional view of arotarv drill constructed in accordance with 'my' invention; Fig. 2 is a bottom plan view ,of same; :Fig. 3 is a side elevational-view of said drill showing it equipped with cutters of slightly different form from those shown; in Fig. 1; and Fig. 4 is a vertical-sectional View illustrating a slight modification of my invention,

Referring to the drawings which illustrate the preferred form of my invention,- A designates the head of the drill which pref-v erably consists of-afblockof-metal provided Specification (,1 Letters Patent.

- Patented Jan.;5, iais.

Application filed November 1, 1918. Serial No. $8,654.

at its upper end with a screw-threaded por- 7 tion 1 for connecting the drill to the stem or tubular-shaped operating member,- not shown, through which the water is introduced into the hole so as to flush out the disintegrated.material. Cutters B are rotatably mounted on the head A so as to cut,

, crush and disintegrate the material when the head rotates, and in the preferred form *of my invention as herein shown the head of. the drill is provided with two cutters that are inclined in such a manner that the lower'portions of same converge toward the longitudinal axis or center of the heady A, but I wish it to be understood that my. in-

vention is notlimited to a drill provided.

with two cutters. By inclining the cutters in this manner and proportioning the cutters and head so that the lower edges or lower portions of the cutters are comparatively'close together, a core will not be left standing at the center of the hole. Furthermore, such a design tends to reduce the shearing strains on the spindles of the cutters and also tends to crowd or force the disintegrated material toward the center of the 'hole into the paths of the streams ofwater that emergefrom' the water holesi inthe head,-the lower ends of said waterholes terminating between the cutters B, as shownin Fig. 2.

While the cutters B are substantially disk-shape, they, of course, are made thick enough so that they will be strong enough to successfully withstand the enormous weight of the drill stemthat is imposed on the'cutters when the drill is'in operation, and in the preferred form of my invention as herein shownthe edges of'the cuttersare backed oil or taperedso that they will con -form approximatelv to the diameter of the hole, as shown in Fig. 2. In otherwords,

in Fig.2, and th'esurfaces 40f said cutters which lie back ofor,beyondthecutting edges 3. crush and disintegrate the material at the bottom'of the hole. "The head A is provided at diametrically" onpositeipoints with twofiat surfaces 5 that incline wardly toward the lower end of the head, as

shown in Fig. 1, and the spindles 6 on which 'the'cutters B are-rotat'ably mounted project outwardly from the head A at right angles to the flat bearing faces 5 on the head. The

head A is preferably designed in such a manner that the portions of same in which the upper ends of the fiat surfaces 5 termina'te project laterally slightly over the cutmm, as shown in Fig. 1, and thus prevent 'the'sharp edges of the cutters from catching on-projections in the hole when the drill 1s being-removed from'the hole. The spin- Qdles 6 are offset slightly or set a trifle to one side of the center of the head, as shown. in Fig. 2", so that the rear sides or edge portions of the cutters B will not drag against the side of thehole, indicated by the circle a:

in Fig. v2, when the head is rotated in the direction indicated by the arrow 1 in Fig. 2. In the embodiment of my invention herein shown the spindles" 6 are screwed into the head A, and .are' provided at their outer ends withienlarged lieadso which lap over the outer faces of the cutters B and thus securely'hold' them in position. Bushings? of bronze orsome'oth'ersnitable material, are

' preferably arranged between the cutters and the spindles, and washers 8 are arranged between the cutters and the head A and be? tween theouter faces of the cutters and the enlarged heads' on the spind es. the heads 6 of the spindles being provided with slots 6 so as to enable the spindles to be; screwed into and out of the head by means of a screw-driver or similar tool.' The enormous weight or downwardpressure which the 'drill stem exerts on; the head A tends to disintegrated material into the path of the 1 will conform app'ro'ziimately to the circular shape of the hole, thereby forming a hole having a concave or rounded bottom. One advantage of such a design is that the shearing strains on the spindles of the cutters are reduced to a minimum, and another advantage is that there is very little tendency for the drill to wabble in the hole, owing to the fact that the bottom of the hole is of such form that the head remains centered, Probablyv the chief advantage, however, of my.

improved drill is that the cutters not only shear off the material from the side of the hole and remain sharp by constantly rubbing against the side of the hole, but they also crush and disintegrate the material at the bottom of the hole and tend to crowd the flushing water. these desirable features resulting from the peculiar arrangement of the cutters and from the combined cutting and crushing surfaces with which each cutter is provided. In other words, my improved drill does not depend for its efficiency only on the keen or sharp edges on the cutters which shear 0d the material from the side of the hole and also dig into the bottom of the hole, but in addition to the with a crushing surface that pulverizes and disintegrates the material at the bottom of the hole when the drill is in operation. The cutters are so shaped and are so'arranged on the head that the rear edges of the cutters do not rub against the side of the hole and thus become dull quickly and consequently the drill can be used for a long period without losing its clearance. The cutters can either be provided with sharp cutting edges and plain or smooth crushing surfaces 4 back of the cutting edges, as shown in Figs. 1 and 2, or, if desired, one cutter can be provided with a sharp edge 3 and with teeth 4 and the other cutter can be provided with a sharp edge and a spiral groove 4: back of said sharp edge or on the tapered crushing surface of the cutter. as shown in Fig. 3; or, if desired, the cutting edges of the cutters may be provided with teeth 3*, as shown in Fig. 4e, and the tapered crushing portions of the cutters may be provided with spiral grooves 4, asshown in Fig. 4, or any other pre erred type of surfaces that will c t and d sintegrate the material.

In the drill shown in Fig. 1 the head A is provided at its upper end with a collar 9 for supporting a lubricant-holder, not shown, and ducts 10 and 11 are formed in the head and in the spindles so as to supply a lubricant to the bearing surfaces of the cutters, thereby keeping the drill thoroughly lubricated when it is in operation.

.In the form of my inventionshown in Fig. 4 a pocket 12 is formed in the head so as to hold the lubricant, and ductsv13 are 7 formed in the spindles 6 so as to conduct the lubricant to the bearing surfaces for the cutters. Water-holes 14; are preferably formed in the top of the 'prclret 12 so as to cause the pressure of the flushing water to be exerted on thelubricant in said pocket. In this form of my invention the spindles 6 not only act to support the cutters. and retain them in operative position on the'hoad, but

sharp or keen edges, each cutter is provided 1 they also act as closures for the pocket or.

chamber in which the lubricant is contained, it being necessary to remove one or both of the spindles 6 in orderto fill the pocket 12 with the lubricating medium.

My improved drill is exceptionally rugged and strong because it comprises only a few.

parts that are large enough to successfully withstand the strains to which they are subjected when the drill is in service. It is of such simple construction that it can be manufactured at a low cost; llilS very efficient for comparatively soft formations owing to the fact that the cutters shear ofl themathey are mounted on, the head in such a manner that the forward edges of same rub constantly againstthe'side of the hole; and furthermore, said cutters are so mounted that they 'will not drag and thus cause the drill to lose its clearance quickly, due to excessive wear of the cutters. The cutters are of such design that the hole which is formed tends to center the drill and prevent it from wabb ing in the hole; id still another desirable feature of the drill 15 that the shearing strains on the spindles of the cutter are reduced to a minimum owing to the fact that the head and the cutters are so designed that the weight imposed on the head tends to force the inner faces of the cutters against the flat inclined bearing surfaces on the head.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A rotary boring drill comprising a head, and approximately disk-shaped cutters rotatably mounted on the head and provided with sharp cutting edges that dig into the bottom-of the hole adjacent the center the hole outside of the cuttingzone of said sharp edges.

2. A rotary boring drill provided with approximately disk-shaped cutters that are inclined in such a manner that the lower i portions of same converge toward the longitudinal axis of the drill, said cutters having sharp cutting edges and also crushing surfaces of less diameter than-said sharp edges that lie outside of same and which disintegrate the material at the bottom of the hole while said sharp edges are shearing off the material from the side of the hole.

3. A rotary boring drill provided with approximately disk-shaped cutters thatare inclined in such a manner that the lower portions of same converge toward the longitudinal axis of the drill, said cutters having crushing surfacesthat disintegrate the material at the bottom of the hole, and also cutting surfaces that shear off the material from the side of the hole anddiginto the bottdrn of the hole adjacent .thecenter of same. a a

f: A rotary boring'drill provided with oppositely disposeddislr-lilre cutters whose lower portions incline inwardly toward the vertical axis of the drill, said cutters being so arranged that the sharp edges of same shear ofi the material at the side of the hole and having crushing surfaces of less diameter than the diameter of the edge portions of the cutters that act on the bottom of the hole. v.

' 5. A boring drillcomprising a head provided with inclined faces that converge downwardly toward thelongitudinal axis of the head, spindles projecting laterally from said inclined faces at approximately right angles thereto, and substantially diskshaped cutters rotatably mounted on said spindles and provided with combined cutting and crushing surfaces that shear off the material at the side of'the hole and also disintegrate the material atthe bottom of. the hole, the crushing surfaces of said cutters lyingoutside of and beingof less diameter than the cutting surfaces that islheiar oil the material from the side of the 6. A rotary boring drill comprising a head, spindles that project outwardly and downwardly from said head, and substantially disk-shaped cutters rotatably mounted on said spindles and provided with crushing surfaces that crush and pu-lverize the material at the bottom of the hole and cutting edges that act on the side wall of the hole, said cutters being of greater diameter at their inner fa-ces than at their outer faces.

7. A rotary boring drill comprising a head provided with substantially disk-shaped cutters that are inclined in such amanner that the lower portions of same converge toward thelongrtudmal axis of the head. said cutters having cutting edges whose advancing portions act on the side wall of the 'hole and one of said cutters having teeth that crush and disintegrate the material at the bottom of the hole.

a 8. A rotary boring drill comprising .a head having a portion that is substantially -V-shaped in vertical cross section, so as to form flat end-thrust-resisting bearings for the cutters, s indles that project laterally from the fiat-faces of said V-shaped portion, and substantially disk-shaped cutters rota.-

tably mounted on said spindles and pro-' vided bevond or outside of their cutt ng edges with tapered crushing surfaces of less diameter than the cutting edgesthat disinjtlegrate the material atthe bottom of; the

disk-shaped cutters rotatably mounted on said spindles and provided with tapered crushing surfaces that disintegrate the material at the bottom of the hole, said cutters having cutting edges that shear ofi the material from the side of the hole and which.

' cutting edges that act on the side wall of the .hole and being provided with broad crushing surfaces 0 less diameter than said cutting. edges that disintegrate the material at the bottom of the hole lying outside of the point where said edges act on the bottom of the hole, and means for discharging streams of flushing water from the lower end of the head between said cutters.

11. A rotary boring drill comprising a head having a pocket formed therein 0t sufficient size to hold a large quantity of lubricant, a rotatable cutter mounted on said head, and a removable spindle for said cutter that acts as a closure for the opening in the pocket through which the lubricant is introduced into same.

12. A rotary boring drill comprising a head provided with a pocketfor holding a lubricant, spindles screwed into said head and acting as closures for the opening through which the lubricant is introduced into said pocket, and substantially diskshaped cutters mounted on said spindles and being so designed that they shear off the material from the side of the hole and crush the material at the bottom of the hole,

said spindles having ducts for" supplying Copies at this patent maybe. obtained aathe lubricant in said pocket to the bearing surfaces for the cuttersr 13. In a rotary boringdrill, a head, an approximately disk-shaped cutter rotatably mounted on said head in such a manner that. the advancing edge of same shears off the material at the side of the hole at a point above the bottom of the hole, and an independent cutter rotatably mounted on said head and provided with teeth for crushing and pulverizing the material at the bottom of the hole lying outside of the zone where the edge of said d sk-shaped cutter acts on the bottom of the hole.

14. In a rotatable boring drill, a head, an approximately disk-shaped cutter rotatably mounted on said head for shearing oft the. material at the side of the hole and digging into the bottom of the hole adjacent the center of the hole, and an independent cutter rotatably mounted on said head provided with teeth for crushing. and pulverizing the material at the bottom of the hole lying outside of the path where said diskshaped cutter d gs into the bottom of the hole, said cutters being inclined in such a mannerthat the lower portions of same coin Eerge toward the longitudinalaxis of the cad.

15.. Ina rotary boring drill, a head, and

an approximately disk-shaped cutter rotatably mounted on the head and provided with a comparatively sharp edge that shears off the material from the side of the hole and with a broad crushing surface that disintegrates the material at the bottom of the hole that lies outside of the point where the edge of the cutter digs into the bottom of tegrates the material at the bottom of the hole lying outside of the zone where said shearing edge digs into the bottom of the hole.

17. A rotary boring drill provided with an approximatelv disk-shaped inclined cutter that has a shearing edge and crushing surface of less diameter than said shearing edge which in horizontal cross section conforms approximately to the curvature of the side wall of the hole.

18. In a rotary boring drill, a head, and

a substantially disk-shaped cutter rotatably mounted on said head and arranged in such a manner that the lower portion of same inclines inwardly toward the longitudinal axis of the head, said cutter having a shearing edge and a crushing portion-of less diameter than said edge and being so mounted on the head thattheforward portion of said edge rubs constantly against the side of the hole and the rear portion of said edge does not drag over the side of the hole.

19. A rotary boring drill consisting of a head. a substantially disk-shaped cutter on said head whose lower portion inclines in wardly under the head. said cutter having a comparatively sharp edge that removes the material from the outer s de of the hole and a crushing portion that lies bevond or outside of said sharp edge for disintegrating the material onthe bottom of the hole, and

a portion on the head that projects laterally In testimonv whereof I hereunto aiiix my s gnature in the presence of two witnesses, this. 27th day of October, 1913.

HOWARD R. HUGHES.

Witnesses: v

'BENJAVIN Annnnws,

E. M. Townes. 7

five cents each. by addressing the Commissioner of Patent wllmgtflmfliw 

